1. Field of the Invention
This invention relates to methods of making a semiconductor chip package, and more specifically to methods of making a low-pin-count chip package by a film carrier.
2. Description of the Related Art
FIG. 1 is a low-pin-count chip package 100 according to a preferred embodiment disclosed in R. O. C. Publication No. 348306 entitled "Device Having Resin Package And Method Of Producing The Same". The low-pin-count chip package 100 includes a chip 110 sealed in a package body 120. The active surface of the chip 110 is provided with a plurality of bonding pads 110a electrically connected to a plurality of connection pads 130. The backside surface of the chip 110 is exposed from the package body 120 through a conductive adhesive layer 112. The connection pads 130 are located around the chip 110 and exposed from the lower surface of the package body 120 for making external electrical connection. The chip package 100 can be mounted onto a substrate, such as a printed circuit board, like other leadless devices.
R. O. C. Publication No. 348306 also discloses a method of producing the low-pin-count chip package 100. The method mainly utilizes a metallic frame 170 (as shown in FIG. 2) to produce a plurality of the chip packages 100 simultaneously. The method includes: (A) forming a photoresist layer over the metallic frame 170, transferring the desired pattern, and developing in a manner that areas on the metallic frame 170 corresponding to the connection pads 130 are not covered by the photoresist layer. (B) Electroplating areas on the metallic frame 170 which are not covered by the photoresist layer with a layer of metal such as gold or platinum thereby forming the plurality of connection pads 130. (C) Removing the photoresist layer. (D) Securely attaching the backside surface of the chip 110 to the metallic frame 170 through an adhesive layer. (E) Electrically coupling the bonding pads of the chip 110 to the corresponding connection pads 130. (F) Forming a package body over the chip 110. Finally, a separation process is taken to remove the metallic frame 170. As shown in FIG. 2, the separation process typically is done by utilizing an etching agent to selectively dissolve the metallic frame 170, with the connection pads 180 undissolved.
The method of making the low-pin-count chip package 100 described above utilizes the metallic frame 170 to support the chip 110 during the assembly process, and then the metallic frame 170 needs to be removed by etching agent. Therefore, the method is quite complicated, expensive and time-consuming.